The proposed new UCLA program will train predoctoral students from the behavioral and social sciences in biomedical theory, evidence, and methods and mentor them to integrate these approaches into health research. The goal is to train interdisciplinary investigators based in population science and health psychology who examine the complex pathways through which demographic, socioeconomic, and psychological processes influence and are influenced by health and disease. The program is a partnership of the UCLA California Center for Population Research (CCPR) and the Program in Health Psychology in the Department of Psychology. The CCPR and the Program in Health Psychology are top centers nationally for research in their respective areas. We request support for 5 predoctoral trainees per year for two year traineeships. Trainees will be selected from students in psychology, sociology, community health sciences, and economics. In the first year, trainees will take a carefully designed year-long didactic training course taught by life sciences and biomedical faculty focusing on the structure and function of key bodily systems which are critical for health and disease and the pathophysiology of major medical conditions. They will also develop a research proposal with two co-mentors, one from the behavioral or population sciences, and one from the biomedical sciences. In the second year, students will apply their first-year coursework via a sequence of laboratory and research experiences. By the end of their second year, trainees will complete an independent research project based on their proposal, co-mentored by a biomedical science faculty member and a population or behavioral science faculty member, and yielding either a dissertation proposal or a manuscript to be submitted for publication. Throughout the traineeship they will participate in a proseminar with faculty and guest speakers that integrate the biomedical knowledge into their scientific approaches. The program will be led by a team of faculty from the population, behavioral, and biomedical sciences that will be overseen and supported by a similarly interdisciplinary committee of Core Faculty. To mentor trainees, provide laboratory and research experiences, and lecture in the didactic training course, we have recruited a large team of distinguished faculty from the population, behavioral, biomedical sciences with outstanding records of publication, extramural funding, and mentoring, as well as extensive experience in collaboration on health research across traditional disciplinary boundaries. Relevance: The program will benefit public health by producing new interdisciplinary investigators who through their research will help to determine the pathways by which individual social, economic, and psychological factors influence and are influenced by health and disease. By virtue of this training, this new cohort of investigators will be better able to identify interdisciplinary approaches to intervention for the benefit of public health in the United States.